Dietary protein is an important macronutrient for human health, and it can be found in a wide variety of foods. To learn more about the basics of protein, check out this earlier article.

Types of Protein Sources

Before we explore the different types of protein food sources, it is important to think about what else comes with it. When you eat foods that are rich in protein, you are also getting other things like fats, fiber, sodium, and other nutrients. Current evidence suggests that the “protein package,” has a greater impact on our health than the amount of protein eaten.

Traditional Animal-based

Source: World Resource Institute (Click on the image to see a larger version.)

Traditional sources like beef, pork, lamb, poultry, and seafood usually come from farms or wild sources. These proteins are complete protein sources because they contain all nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Additionally, animal-based protein is referred to as “high-quality” protein due to its high concentration of amino acids and digestibility, rather than its impact on human health or the environment. Regardless, it is important to note that not all animal-based proteins are created the same.

Red and Processed Meats

Red meats like beef, pork, and lamb, and processed meats, such as luncheon meats, hot dogs, and jerky, are high in saturated fats; furthermore, processed meats also contain a high amount of sodium. High intake of red meat, especially processed meats, has been linked to increased risk of cardiometabolic diseases, like heart disease, stroke and type 2 diabetes, and various cancers.

Dairy

Dairy products like milk, cheese, and yogurt are good sources of calcium, protein, and other important nutrients. But they can also have a lot of saturated fat, so it is better to consider the low-fat options.

Poultry and Eggs

Poultry, like chicken and turkey, is defined as a “high quality” and complete protein source like red meat. However, poultry, unlike red meat, generally has a lower saturated fat content; a notable exception to this generalization is duck. Eggs are also a complete source of protein with healthy fats and other nutrients.

Seafood

Seafood, such as salmon, Pacific oysters, tuna, and whitefish contain important types of omega-3 fatty acids, like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acids are a type of polyunsaturated or “healthy” fat; they play an important role in cellular membrane function and support the function of the cardiovascular and endocrine systems. The major concern involved in consuming seafood, specifically fish, is the amount of mercury present; however, these levels vary between species. For advice on eating fish, check out this article from the FDA.

Plant-based

Beans, Peas, Lentils, Grains, and Soy

Beans, peas, and lentils are great plant-based proteins that also give you fiber, vitamins, and minerals. However, typically, a single type of bean, pea, or lentil does not constitute a complete protein by itself. It is advised to mix different types or add other foods to get complete protein, like the classic combination of rice and beans. Soybeans and soy products, like tofu and tempeh, are also a good source of protein, especially for those on a vegan and vegetarian diet. Rice is also a good source of protein, but like other plant-based sources, does not provide a complete protein and should be combined with other foods to ensure adequate intake.

Nuts and Seeds

Nuts and seeds like almonds, peanuts, chai seeds, and sunflower seeds, are a good source of protein and healthy fats. However, due to their high fat and calorie content be mindful of your portion sizes. Quinoa, which is often classified as a pseudo-cereal but is a seed, is a complete protein.

Microbe-based

Microbial protein comes from microorganisms, mainly fungi (such as yeasts and filamentous fungi), microalgae (like cyanobacteria), and bacteria. The utilization of microbes for protein and food processing is not a new idea and can be observed in the making of bread, yogurt, and cheese, as well as in the direct consumption of yeast and algae. Two of the most well-known types of microbe-based proteins are nutritional yeast and spirulina. Some of the limitations of microbe-based proteins are the cost and product quality. They are not considered a complete protein because microbial protein only has eight out of the nine essential amino acids.

Insect-based

The practice of consuming insects, such as grasshoppers, ants, bees, and caterpillars, has long been established in several cultures throughout South and Central America, Africa, Asia, Oceania, and Europe. Insect-based protein is similar in quality to that from livestock but is more resource-efficient. However, it is important to consider species-specific health concerns, such as potential microbial, allergenic, and toxicological risks.

Cultivated Animal-based

Cultivated or lab-grown meat is an innovative technology that could transform the traditional meat industry. This process involves extracting cells from an animal, without slaughter, and then the cells are grown, harvested, and processed into meat for human consumption. The first lab-grown meat, a beef burger patty that cost $330,000, was developed by a scientist in the Netherlands in 2013. Since then, technological advancements have expanded product offerings to include cell-cultivated versions of pork, chicken, and seafood. The significant challenges facing the cultivated meat industry include scaling up production, reducing the costs of finished products, and replicating the taste and texture of conventional animal products. Still, since it comes from animal cells, it is a complete protein source.

Conclusion

Each protein source comes with its unique set of nutrients, which collectively impact our health more than the protein content alone. Understanding the complexities of each protein source—from traditional animal-based proteins to innovative lab-grown meats—helps us make informed dietary choices that align with our needs and considerations.